Many industrial reactions use a mixing tank reactor with slurry of a solid catalyst. In the reactor, liquid is contacted with a reactive gas such as hydrogen or ammonia gas in the presence of the catalyst to progress a reaction. After the reaction, the catalyst is generally removed by filtration, and a reaction product is collected.
However, the catalyst in a slurry form has problems in safety, increased amount of waste, operability, productivity, and the like. For example, many of catalysts are pyrophoric, and catalysts in forms of powder and slurry require careful handling. These catalysts also have problems of complicated facilities and operations, because these must be removed by, for example, filtration to collect a reaction product.
One of processes that do not require operations for mixing such as stirring and bubbling with gas and for separating a catalyst by filtration is a fixed-bed process. For a formed catalyst used in the fixed-bed process, those have conventionally been known, including pellet, noodle, and tablet catalysts. A powder material having a catalytic activity is molded, for example by pressing or extruding, into an intended structure being very porous and having both the above shown form and a large surface area. For example, JP-A 6-211754 discloses such a catalyst.
The fixed-bed process can solve problems such as handling of a catalyst and waste, but is applicable to not so much reactions. For example, in endothermic and exothermic reactions, there are problems of temperature control, nonuniform distribution of liquid-gas in a reactor to result in insufficient reaction rate, and topically concentrated distribution to cause side reactions.
A reaction of an alcohol with a primary or secondary amine in the presence of a formed catalyst described in JP-A 6-211754 in order to produce a tertiary amine at high reaction rate results in not a little amount of undesired bi-products. Examples of the bi-product include waxes and aldol condensation products from the starting alcohol by side reactions, ammonias derived from disproportionation of the primary or secondary amine, and tertiary amines produced by side reactions of the primary or secondary amine. To highly selectively produce an intended product with a reduced amount of such bi-products, many attempts to improve the method have been done. However, the reaction has been difficult to be performed at high selectivity by a simple process in the past.
To overcome the disadvantage of production of a tertiary amine in the presence of such a formed catalyst, WO-A2005/035122 discloses a method of producing a tertiary amine in the presence of a film catalyst.